What about climate change?

Last month, a Republican-aligned polling firm called on hunters and fishermen nationwide to get their views. Some of the results were unsurprising: Outdoorsmen regard themselves as politically conservative and register Republican over Democratic by a more than 2-to-1 ratio.

But here's one response that may have caught President Barack Obama and his re-election team by surprise, if they noticed it at all: A majority of these sportsmen believe global warming is the cause of this past summer's high temperatures and want the White House and U.S. Environmental Protection Agency to limit carbon dioxide and other greenhouse gas emissions.

In other words, these die-hard Second Amendment-loving deer hunters and fly fishermen feel strongly that the U.S. must do more about climate change. The poll by Chesapeake Beach Consulting found outdoorsmen support conservation measures as much as they do gun rights. And they are not exactly a fringe group: the National Wildlife Federation, which financed the poll, estimates there some 37 million Americans engaged in hunting or fishing.

So if climate change is a priority for so many people in this country — including a whole lot who identify themselves as conservative and GOP-leaning — why has there been virtually no mention of arguably the most pressing environmental issue of the day in the presidential election? Mitt Romney's reluctance is understandable, as he's waffled around it over the years. If Mr. Romney is not an outright denier, he's at least a down-player. He declared on national television last month that he's "not in this race to slow the rise of the oceans or to heal the planet," and he said something similar at the Republican National Convention.

Mr. Obama's failure to raise the issue, however, is bewildering to many in the environmental community since his support for doing more about global warming has been clear cut (although not always a high priority). This year's extraordinary weather events — droughts, floods, heat waves and the like — have only made climate change more real to average voters. And climate scientists say the problem is worsening at an accelerating rate, so the urgency is there.

But here's the real puzzler: It could be a winning issue with undecided voters, those considered most crucial in this tight race. A recent poll by Yale and George Mason universities found 80 percent of undecided voters believe that global warming is happening, compared to 3 percent who claim it isn't. Two-thirds of them believe the federal government should do more about climate change, and more than 60 percent say it's an issue they'll consider in their selection of a president.

So, to review: The evidence of climate change has never been more convincing, the incumbent is head-and-shoulders above his challenger on the issue, and voters — particularly those who could swing the outcome of this year's race — are receptive to that message. It's a classic wedge issue. So why have two presidential debates gone by without a single mention of climate change, and why has it not been a featured element in the stump speeches?

The only real possibility for Mr. Obama's reluctance to attack his opponent is that he worries that the issue might be used against him. Concern for the environment might translate into a lack of interest in people and jobs. That's clearly how the GOP is playing it. Republicans have tried to make the case that the U.S. has gone too far in environmental protection and hurt the private sector's ability to expand and create new employment opportunities. "By the way, I like coal," as Mr. Romney likes to say.

If so, it's an extremely short-sighted approach by the Obama team. To do nothing about climate change is to accept disaster to human beings on a planetary scale. Millions of lives could be lost. And it's also outrageous to accept the premise that clean air, land and water are somehow not in the public interest. Polluters may feel that way, but voters sure don't.

This is not an issue from which to run and hide. When Mr. Romney and other conservatives pooh-pooh climate science, they sound a great deal like those who dismissed Darwin and evolution. That may continue to play well in some Republican primaries, and certainly, people have a right to their know-nothingness, but they don't constitute a majority in this country. Mr. Obama needs to wake up and recognize that addressing climate change should not only be a high priority for the nation, it ought to be central to his re-election message.